ThreatFox: Vidar IOCs

Hunt Hypothesis

This hunt targets the presence of Vidar malware indicators, a remote access trojan frequently used for credential theft and lateral movement, by correlating its known IOCs against Azure Sentinel telemetry. Proactively hunting for these signatures allows the SOC to identify compromised endpoints early, preventing the adversary from establishing persistent access and exfiltrating sensitive data before traditional detections trigger.

IOC Summary

Malware Family: Vidar Total IOCs: 4 IOC Types: domain, url

KQL: Domain Hunt

// Hunt for DNS queries to known malicious domains
// Source: ThreatFox - Vidar
let malicious_domains = dynamic(["hh.hg77.org", "hh.1betasia.org"]);
DnsEvents
| where Name has_any (malicious_domains)
| project TimeGenerated, Computer, Name, IPAddresses, QueryType
| order by TimeGenerated desc

KQL: Url Hunt

// Hunt for access to known malicious URLs
// Source: ThreatFox - Vidar
let malicious_urls = dynamic(["https://hh.1betasia.org/", "https://hh.hg77.org/"]);
UrlClickEvents
| where Url has_any (malicious_urls)
| project Timestamp, AccountUpn, Url, ActionType, IsClickedThrough
| order by Timestamp desc

Required Data Sources

References

• ThreatFox — Vidar

False Positive Guidance

• Legacy Application Maintenance via Scheduled Tasks: A legacy line-of-business application (e.g., an older ERP or inventory system) uses a scheduled task to run a maintenance script that creates a temporary log file or configuration dump in the %TEMP% or AppData directory with a name matching one of the Vidar IOCs (e.g., config.dat or a specific hash).

  • Filter/Exclusion: Exclude alerts where the parent process is a known service executable (e.g., svchost.exe running a specific service, or the application’s own .exe) and the file path is under the application’s dedicated AppData or Program Files directory, rather than generic user temp folders.

• Third-Party Software Installer Behavior: A widely used enterprise software installer (e.g., Adobe Creative Cloud, Java, or a specific vendor’s management agent) creates a temporary registry key or file during installation or update cycles that matches a Vidar IOC (such as a specific registry path like HKCU\Software\Microsoft\Windows\CurrentVersion\Run with a benign value name, or a temporary file hash).

  • Filter/Exclusion: Correlate the alert with recent software deployment events (e.g., SCCM/Intune deployment logs) and exclude if the process is a known installer (e.g., msiexec.exe, setup.exe from a trusted vendor path) and the event occurred within a 15-minute window of the deployment.

• Development or QA Environment Testing: Developers or QA engineers running Vidar-related test cases, or using a tool that mimics Vidar’s behavior for testing purposes (e.g., a security testing framework or a specific debugging tool), create files or registry entries that match the IOCs.

  • Filter/Exclusion: Exclude alerts originating from user accounts tagged as Developer, `QA